Why Outdoor Exercise Rules

Reason #1: You'll Want to Exercise

Your 2013 get-fit plan got old faster than "Gangnam Style"? Breathe some fresh air into a tired routine (hey, the weather's on your side), and chances are, you won't blow off your next workout.

The Proof You're 23 percent more likely to repeat an outside session, or so an Ohio State University study suggests. A group of twentysomething women compared doing the same workout (they were walkers) indoors versus out, and no-walls won because it felt more, wait for it, fun!

Arthur Belebeau

Reason #2: No More I-Can't-Sleep Nights

Choose a sunrise workout and you could fall asleep when you want at night—up to an hour sooner.

The Proof Natural a.m. light resets circadian rhythms, so it may be easier to nod off, say experts at the Lighting Research Center in Troy, New York. Avoid a sunset session; it can delay melatonin release, making it tougher.

Colette De Barros

Reason #3: You: "Why Is This So Easy?"

Just seeing the color green while you move might make you feel superhuman.

The Proof Cyclists rated a ride 10 percent easier with a green backdrop, likely due to its calming effect, finds a study in Environmental Science & Technology. Thank you, trees.

Stephanie Rausser

Reason #4: It's Like Prozac!

Exit building, enter happy zone.

The Proof After a measly five minutes of any outdoor exercise, you're happier and more confident, a University of Essex study finds. Best news: That lift can last alll day.

Arthur Belebeau

Reason #5: Genius Will Strike

But you've gotta leave your gadgets at home.

The Proof After a four-day hike sans tech, people did 50 percent better on a creativity test. University of Utah researchers say an hour of nature time yields some bennies, if you unplug. Smarter without a smartphone.

Arthur Belebeau

Reason #6: Stupid-High Energy

Nature is your new venti skim latte.

The Proof Just 20 active minutes outside can wake up your body and mind, making you feel more alive, University of Rochester researchers say. And it doesn't cost you $4!

Arthur Belebeau

Reason #7: Um, Fewer Germs!

What you don't have to stress about when sweating alfresco: a gross staph infection.

The Proof Ten percent of gym surfaces tested positive for the bacteria in a Virginia Commonwealth University study. Ewww.

Nicola Majocchi

Reason #8: You'll Zen Out

You know that sense of peace you get jogging in a park? Not your imagination.

The Proof Exercisers reported being less tense and tired, and calmer, during any activity done outside rather than in, probably because those surroundings felt more serene, a Santa Clara University study notes.